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  • 1.BUILDING MATERIALSSANDAr. Ravindra Patnayaka B.Arch, M.Tech (Planning) Assistant Professor in Architecture

2. SAND Sand is a naturallyoccurring granular material composed of finelydivided rock and mineral particles. the most common constituent of sand is silica (silicondioxide, or SiO2), usually in the form of quartz. 3. SOURCES OF SAND Sand is formed by the weathering of rocks. Based on the natural sources from which sand is obtained, it is classified as follows: Pit sand River sand Sea sand 4. PIT SAND Thissand is obtained by forming pits in soils. It is excavated from a depth of about 1-2 m from the ground level. This sand is found as deposits in soil and it consists of sharp angular grains, which are free from salts. 5. Pit Sand It serves as an excellent material for mortar orconcrete work. Pit sand must be made free from clay and other organic materials before it can be used in mortar. A coating of oxide of iron over the sand grains should be removed. 6. RIVER SAND This sand is widely used for all purposes. It isobtained from the banks or beds of rivers and it consists of fine rounded grains. The presence of fine rounded grains is due to mutual attrition under the action of water current. 7. River sand The river sand is available in clean conditions. The river sand is almost white in color. 8. River sand 9. SEA SAND This is obtained from sea shores. It is brown in color and it also has the finerounded grain. 10. Sea sandDREDGED SAND DESPOSITION 11. Sea sand As it is obtained from sea it contains salt, which isused in attracting moisture from atmosphere. Such absorption causes dampness and disintegration of work. It is generally not used for engineering purpose due to its retards setting action of cement. It is normally used for non structural purposes. 12. Crushed Stone Sand / Artificial Sand It is a substitute for River Sand, fine aggregateswhich manufactured by crushing either granite or basalt rock using 3 stage crushing process. This sand is manufactured in conformance to IS Codes and is an effective alternative to river sand. 13. CLASSIFICATION OF SAND Based on the grain size distribution Fine sand: The sand passing through a sieve withclear openings of 1.5875 mm is known as fine sand. Fine sand is mainly used for plastering. . Coarse sand: The sand passing through a sieve with clear openings of 3.175 mm is known as coarse sand. It is generally used for masonry work. Gravelly sand: The sand passing through a sieve with clear openings of 7.62 mm is known as gravelly sand. It is generally used for concrete work. 14. Grading of sand: On the basis of particle size, fine aggregate isgraded into four zones. IS SievePercentage passing for Grading Zone Grading I Zone IIGrading Zone IIIGrading Zone IV10mm1001001001004.75mm90 10090 10090 10090 1002.36mm60 9575 10085 10095 1001.18 mm30 7055 9075 10090 100600 micron15 3435 5960 7980 100300 microns5 208 3012 4015 50150 microns0 100 100 100 15 15. Sand for Construction Works Different construction works require different standards of sand for construction. Brick Works: finest modulus of fine sand should be 1.2 to 1.5 and silt contents should not be more than 4%. Plastering Works: finest modulus of fine sand should not be more than 1.5 and silt contents should not be more than 4%. Concreting Works: coarse sand should be used with finest modulus 2.5 to 3.5 and silt contents should not be more than 4%. 16. PROPERTIES OF GOOD SAND It should be clean and coarse. It should be free from any organic or vegetable matter; usually 3-4 per cent clay is permitted. It should be chemically inert. It should contain sharp, angular, coarse and durable grains. It should not contain salts which attract moisture from the atmosphere. It should be well graded, i.e., it should contain particles of various sizes in suitable proportions. It should be strong and durable. It should be clean and free from coatings of clay and silt. 17. Tests To check the quality of fine aggregates or sand; put some quantity of sand in a glass of water. Then it is vigorously shaken and allowed to settle. If the clay is present in sand, its distinct layer is formed at the top of sand. To detect the presence of organic impurities in sand, a solution of sodium hydroxide or caustic soda is added to sand and stirred. If the color of solution changes into brown, it shows presence of impurities. 18. BULKING OF SAND The increase in the volume of sand due to thepresence of moisture is known as bulking of sand. This is due to the fact that moisture forms a film of water around the sand particles and this results in an increase in the volume of sand. The extent of bulking depends on the grading of sand. The finer the material the more will be the increase in volume for the given moisture content. For a moisture content of 58 per cent, the increase in volume may be about 2040 per cent depending upon the gradation of sand. When the moisture content is further increased, the sand particles pack near each other and the amount of bulking is decreased. Hence, dry sand and the sand completely 19. Deleterious materials in sand Sand shall not contain any harmful impurities such asiron, pyrites, alaklies, salts, coal or other organic impurities, mica, shale or similar laminated materials, soft fragments, sea shale in such form or in such quantities as to affect adversely the hardening, strength or durability of the mortar. The maximum quantities of clay, fine silt, fine dust and organic impurities in the sand / marble dust shall not exceed the following limits: (a) Clay, fine silt and fine dust when determined in accordance within not more than 5% by mass in IS 2386 (Part-II), natural sand or crushed gravel sand and crushed stone sand. (b) Organic impurities when determined in color of the liquid shall be lighter in lighter in accordance with IS 2386 (Part II) than that specified in the code. 20. references http://theconstructor.org/concrete/joints-in-concrete-structures/970/ http://www.wikihow.com/Make-Concrete